MICROBIAL PROCESSES OF CARBON AND SULFUR CYCLES IN BOTTOM SEDIMENTS OF LAKE-MICHIGAN

The distribution and activity of saprophytic, cellulolytic, sulfate-re ducing, and methanogenic bacteria was studied in bottom sediments of L ake Michigan and Green Bay. Maximal abundance of these bacteria was fo und in the upper horizons of the sediments. The intensity of cellulose decomposition and sulfate reduction declined toward the lower horizon s; on the contrary, the rates of acetate and methane formation increas ed. The maximum rate of Mn4+ reduction was recorded in the under-surfa ce layers.